Automotive boiler system



Sept. 24, 1929. C, A, FRENCH 1,729,102

AUTOMOTIVE BOILER sYsTEu Filed June 8, 1922 w 0900000 0 9 9 0 09 C @C Patented Sept. 24, 1929 UNITED STATES PATENT OFFICE CHARLES A. FRENCH, OF CHICAGO, ILLINOIS, ASSIGNOR TO INTERNATIONAL HAR- VESTER COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY Application led June 8,

My invention relates to an automotive power plant and a boiler to be used therein and is an improvementT on the power plant and boiler shown in my co-pending application Serial No. 566,710 filed June 8, 1922. In my co-pending application, the preheater, evaporator and superheater coils are all connected to a steam drum, the heating surfaces of the dilerent zones being constant for all loads and rates ofV steaming and the burner which is controlled by boiler pressure is located beneath the boiler and discharges its hot gases into the center of the boiler from whence they flow radially outward over the several coils.

In the present application, the preheater, evaporator and superheater coils are continuous, one with the other, and the respective areas change with variations in the heat from the burner and the rate at which water is supplied and steam consumed. The burner is of a modified construction and is placed above the boiler where. it is more effectively heated to vaporize the fuely and discharges its hot gases downward intorthe center of the boiler from where they flow radially' outward over the coils.

My improved boiler has one continuous coil surrounding the fire which is at the center and there are no sharp bends in thetube.

Waternters the outside coil and flows toward the center giving a lcounterilow of the water and hot gases so that the greatest possible amount of heat is extracted from the 35. gases.

Water from the. condenser is continuously being pumped into the outer coil and progresses steadily toward the tire at the center.

At some variable point, steam begins to be 40 formed and continues to do so until all the water is vaporized at another variable point. The -steamcontinues to travel through the l coils toward the burner with increasing superheat until it -linally` leaves the boiler '45 through a water regulator on its way to the engine which exhausts into the condenser.

The pump is always returning the water to the boiler as fast as it is used so that there `is practically always the same amount of water (liquid and steam) in the boiler and,

1922. serial No. 566,712.

hence, there is no occasion for the water regulator to act except when leakage or a possible pump failure so reduces the amount of water in the boiler that the degree of superheat in the steam becomes too high.

The burner is of sufficient size tovaporize and superheat the maximum steam demandedfand is 'automatically turned off when kthe boller pressure rises toa predetermined maximum and automatically turned fully on when the pressure drops a definite amount below the maximum. At any load less than the maximum, water will be evaporated faster t-han it is pumped in as the pump supplies the water at approximately the same rate that steam is taken out of the boiler so that the steaming zone gradually moves away from the fireand the pressure-and superheat increases. This is true because the water that evaporates to allow the steaming zone to recede is still in the boiler and occupies more space as steamthan it did as water, consequently raising the boiler pressure. Before this process has continued very long, the pressure will reach that point at which the automatic pressure regulator operates to shut olf the., burner. The use of steam from the boiler now` reduces the pressure and, since water is still being pumped into the boiler, the division between the steam and water advances toward the center until the pressure regulator operates to start the burner again. The pressure regulator is adjusted to operate within av comparatively short range (from 500 to 600 pounds boiler pressure), hence, the range of movement of the steaming zone in the boiler will be quite small.

If water isvlost from the system, or, if for any other reason, the feed pump does not return as much water as is being taken out as steam, the steaming zone will recede faster than the steam pressure increases so that before the fire is shut oli by the pressure regulator the superheating zone will have become large enough to give too high a temperature 95 to the steam. When this occurs, the mercury vapor thermostat will operate to admit water tol the system from a4 storage tank. When sufficient water has been added to thesystem.

.to restore the steaming zone to its normal lo- 100 cation, the superheat in the steam will have reduced, coolingthe thermostat and closing the supply 'of water from the storage tank. In the event that there is no water in reserve or that the feed pump fails to deliver water to the boiler, the steam temperature will ining in which I have illustrated one embodi- -from the auxiliary engine.

ment thereof.

My improved boiler has an outer casing 1 into which a burner 2 discharges its hot gases, the gases leaving the casing through a downwardly discharging annular flue 3. Within the casing there is a continuous coil 4 having an inlet 5 at one end receiving water from a pump 6 and an outlet 7 at the other end discharging to the steam main 8 from whichI branches lead to the main engine 9 and auxiliary engine 10 driving the feed pump 6. Both engines exhaust into the condenser 11 water from which flows through pipe 12 into a reservoir or hot well 13 from which the feed pump draws its supply.

The burner 2 is supplied with a mixture of fuel and air by means ot blower 14 driven In the conduit 15 connecting the blower and burner are two butterfly valves 16, 17 connected to a pressure regulator 18 and a water regulator 19 respectively. The pressure regulator is connected .to the coil 4v preferably at a point about midway of its ends but any desired point of connection is suitable. The boiler normally works between minimum and maximum pressures of 500 and 600 pounds per square inch and the regulator is adjusted so that it will close the throttle 16 to shut off the burner vwhen the pressure `exceeds`600 pounds and open the throttle to turn on the burner when the pressure drops to 500 pounds.

The water regulator 19 has a. chamber 20 through which the steam from the boiler flows and within which there is a bulb21 filled with an expansible fluid, (preferably .mercury which vaporizes without injury under the highest degree of superheat at which the boiler may work), which is free to expand against one side of a diaphragm 22, the otherA side of which is in contact with the liquid filling the corrugated tu'bev23. y The tube 23 is free to expand at its lower end and engages the stem 24 of a valve 25 controlling the flow of water from an auxiliary reservoir 26 to the-hot wellv 13. One end of a' lever 27 engages under the tube 23, the other end being' connected by a link 28 to a trip lever 29 which engages the arm 30 to hold the throttle 17 open against the tension of a spring 31.

When, through leakage or failure of the water supply for any reason, the pump 6 does not supply water to the boiler as i'astas steam is being consumed, the temperature of the superheated steam will finally become so high that the mercury pressure in the hulb 21 will be increased and the ex ansion against the diaphragm will force ad itional liquid down into the corrugated tube expanding it and opening the valve 25 to supply additional water to the hot well 13. As soon as the normal amount of water is again supplied to the boiler, the degree of superheat returns to normal, the mercury vapor pressure becomes reduced and the valve 25 closes. If, however, the temperature of the steam continues to rise, the tube will continue to expand against the lever 27 which will rock the trip lever 29 about its pivot .until the arm 30 is released and the throttle 17 closed by the spring 31.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is :v

1. In a steam power plant, the combination of a boiler, a burner, means for supplying combustible mixture to the burner, means for supplying water to the boiler, means for shutting o the burner when the boiler pressure rises to a predetermined maximum, and sin le means for supplying additional water to t e boiler when the steam therein attains a predetermined temperature, and for shutting off the burner when the steam attains another predetermined but still higher temperature.

2. In a steam power plant the combination of a boiler, a burner, means for supplying water'to the boiler, and means for supplying additional water to the boiler when a predetermined temperature is reached in the boiler due to a failure of the first watersupplyingmeans, the same means shutting olf the burner .when another predetermined but higher tem perature is reached in the boiler.

3. In a steam power plant, the combination of a boiler, a. burner,- means for supplying water to the'boiler, means for supplying 4com- Abustible mixture to the burner, and a control member .operable in.. one position of l adj ust ment to supply additional water from another supply means to the boiler when the steam therein reaches a predetermined tempera-ture due to a failure of the first water supply means and in another position of adjustment toshut olf the burner when the steam reaches another but st' l higher temperature.

4. In a. close steam power plant system, a boiler, a burner therefor, control means for said burner, a main water supply for the boiler, a reserve water supply connected with said main water supply, and means in communication with the-boiler and controlling sald connectlon between the ma1n and reserve l Water supplies for causing the reserve supply to replenish the main supply when the Ilatter fails, said means additionally operating said burner control means for shutting olf the burner upon an extreme critical temperature 'condition in the boiler..

In testimony whereof I ailix my signature.

CHARLES A. FRENCH. 

